What is mastitis?

Mastitis is an inflammation of the breast tissue. It can happen anytime, although it usually occurs during the early months of breastfeeding. The inflammation can be infectious (caused by bacteria) or noninfectious. Women with mastitis often say they feel like they have the flu.

Symptoms usually appear quickly and include: 

  • Weakness 
  • Headache 
  • Nausea 
  • Soreness 
  • Chills 
  • Fever higher than 101°F (38.4°C) 
  • Redness, warmth, and aching in part or all of the breast 

Infectious mastitis is caused by bacteria that enter the breast through a break in the skin or an opening in the nipple. Mothers at greatest risk for mastitis are those who have had mastitis before, those with cracked nipples or plugged ducts, or those who wear tight-fitting bras that make milk removal difficult. Delaying or skipping feedings, or failing to drain the breasts fully, can also contribute to mastitis. For reasons that are unclear, illness, fatigue, and stress increase a mother’s risk for mastitis. 

Symptoms of mastitis worsen quickly and include pain, swelling, redness, fever, a rapid heart rate, and severe flu-like symptoms. If left untreated, mastitis can lead to a breast abscess (a collection of infected fluid beneath the skin, which requires medical intervention). 

If you experience symptoms of mastitis, call your health care provider right away, but continue to breastfeed. If you have mastitis, your doctor can prescribe an antibiotic that is safe to take while breastfeeding. Although your symptoms will improve within 24–48 hours, you will need to complete the course of antibiotics, usually 14 days, to ensure that the infection does not reoccur. In mild cases of mastitis, antibiotics may not be prescribed at all.

Other strategies for managing mastitis include: 

  • Keep breastfeeding. Draining the breast helps to keep the infection from damaging the breast tissue. Your milk will not harm your baby. Breastfeed every 1–3 hours during the day and every 2–3 hours at night. Usually only one breast is affected. Start each feeding on the uninfected breast until you feel a let-down reflex occur, then switch to the infected breast; return to the first breast after you baby has drained the infected breast.
  • Apply warmth. Place a warm washcloth on the infected area before each feeding, for up to 15 minutes at a time. This will aid let-down and relieve pain. Warm showers or baths also work well.
  • Apply cold. Apply a cold pack after each feeding to relieve pain and reduce swelling. A bag of frozen peas wrapped in a cold washcloth works well.
  • Rest. Get plenty of rest while you are recovering from mastitis.
  • Stay hydrated. Drink enough fluid to satisfy your thirst. Water and unsweetened juice are best.
  • Take a pain reliever. Acetaminophen or ibuprofen—both safe options for breastfeeding mothers—can help relieve pain and reduce swelling.

To prevent mastitis from reoccurring: 

  • Pay attention to your baby’s position during feeding. If your nipples are cracked, a lactation consultant should be able to help identify any problems with your baby’s position or latch.
  • Don’t delay or skip feedings. If you miss a feeding or your baby feeds poorly, express some milk by hand or with a breast pump to soften the breast and relieve fullness.
  • Vary your baby’s position at the breast. Use two or three different breastfeeding positions throughout the day to ensure that all parts of the breast are being well drained.
  • When it's time to wean your baby from the breast, do so gradually. Your breasts should adjust to the change in demand without pain or problems. (Learn tips on how to gradually wean your baby here.) 

Last updated April 7, 2020

Suggested Reads